It is known to build dust filters into the intake channels of vehicle cabins for providing fresh air. These dust filters retain the dust carried with the air, but otherwise they are not able to meet the requirements for an active protection of the passengers in the cabin against pollutants, which are carried by the air. Pollutants are found in the intake fresh air in particular with high traffic densities and such pollutants include for example hydrocarbon compounds, nitrogen oxides, acid gases (for example sulfur dioxide and other sulfur compounds as well as carbon dioxide). In addition, the intake fresh air contains carbon monoxide. It is in fact known that such pollutants can be removed from the air by way of chemisorption masses, however their use in the fresh air intake for vehicle cabins has failed so far based on the expensive construction requirements and the costs to be paid. The situation with labor protection cabins is similar, where also air containing pollutants can enter.